In order to interface an integrated circuit with other circuitry, it is common to mount it on a lead frame or substrate. Each integrated circuit has bonding pads that are individually connected to the lead frame's lead finger pads using extremely fine gold or aluminum wires. The assemblies are then packaged by individually encapsulating them in molded plastic or ceramic bodies to create an integrated circuit package.
Integrated circuit packaging technology has seen an increase in the number of integrated circuits mounted on a single circuit board or substrate. The new packaging designs are more compact in form factors, such as the physical size and shape of an integrated circuit, and provide a significant increase in overall integrated circuit density. However, integrated circuit density continues to be limited by the “real estate” available for mounting individual integrated circuits on a substrate and the size of the packages. Even larger form factor systems, such as PC's, computer servers, and storage servers, need more integrated circuits in the same or smaller “real estate”. In particular, the need for portable personal electronics, such as cell phones, digital cameras, music players, PDA's, and location-based devices, has further driven the need for integrated circuit density.
This need for increased integrated circuit density, has led to the development of multi-integrated circuit (chip or die) packages in which more than one integrated circuit can be packaged. Each package provides mechanical support for the individual integrated circuits and one or more layers of interconnect lines that enable the integrated circuits to be connected electrically to surrounding circuitry. Current multi-integrated circuit (chip or die) packages, also commonly referred to as multi-integrated circuit (chip or die) modules, typically consist of a PCB substrate onto which a set of separate integrated circuit components is directly attached. Such multi-integrated circuit (chip or die) packages have been found to increase integrated circuit density and miniaturization, improve signal propagation speed, reduce overall integrated circuit size and weight, improve performance, and lower costs—all primary goals of the computer industry.
There is always a limitation on the number of die that can be stacked in a package, especially for big memory dies. Same die stacking with all bond pads located at one side allows stacking in the staircase manner, which can eliminate the need for thick spacers between the dies. However, die stacking is still restricted by the package size where over-stacking causes die protrusions that require extra long packages.
Thus, a need still remains for a reliable and improved integrated circuit package system, method of fabrication, and design, wherein the integrated circuit package system exhibits a high level of functional integration, decreased package size, and ease of manufacturability. Moreover, in view of the shrinking size of consumer electronics and the demand for more sophisticated functions in the restricted space, it is increasingly critical that answers be found to these problems. Additionally, in view of the ever-increasing commercial competitive pressures, increasing consumer expectations, and diminishing opportunities for meaningful product differentiation in the marketplace, it is increasingly critical that answers be found to these problems. Furthermore, the ever-increasing need to save costs, improve efficiencies, and meet such competitive pressures adds even greater urgency to the critical necessity that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.